Counting devices



y 26, 1955 H. BUD ETAL 2,713,971

COUNTING DEVICES Filed Sept. 14, 1951 2 Sheets-Sheet l Inventor Ha -s ZL/jam! H: GREEA/HOW Attorney July 26, 1955 H. BUD ETAL 2,713,971

COUNTING DEVICES Filed Sept. 14, 1951 2 Sheets-Sheet 2 Inventor Hills 3 20.4! HQH GREEA/HDW B WlZ Attorney Patented July 2%, 955

CGUNTHNG DEVICES Southgate, London, and Harry Greenhow, A

iondon, England, assignors to English chines Limited, Enfieid, England, a

The present invention relates to counting devices, and more specifically to a counting device intended for counting aggregates each comprising the same large number of elements, the counting device being responsive to each element.

For example, in connection with diesel and other engines running at a substantially constant speed, it is sometimes required not to count each individual rotation of the engine shaft but large aggregates of such rotations, namely the number of rotations per hour, in order to ascertain how many hours the engine has been running. To this end, a counter may be coupled to the engine shaft over a reduction gear so that the counter is running in dependence on the rotations of the engine shaft, and advances by one unit digit when the number of rotations actualiy performed by the engine shaft corresponds to the number of rotations per hour. In this example, the number of rotations per hour represents an aggregate the elements of which are the individual rotations to which the counting device is responsive. By counting these aggregates, the time in hours may be ascertained during which the engine has been running, and, thus, the counter may be calibrated in hours, each hour corresponding to one unit digit of the counter. In another example, the counter may be intended to count lots of articles, each lot comprising the same large number of individual articles, the counter being responsive to each article but advancing by one unit digit when the number of articles corresponds to the number of articles contained in each lot.

It will be appreciated that in these and similar cases, a reduction gear is required which allows an unusually high reduction.

It is an object of the invention to provide a counting device comprising such a reduction gear which, notwithstanding its high reduction, may be accommodated within a reasonably small space so that it may be combined with the counting mechanism to constitute with it a constructional unit, while yet the counting device is reliable in use, is easy and cheap to manufacture, and is flexible in the sense that it may easily be adapted during its assembly to the requirements of each particular case without affecting the general design of the counting device.

Other objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of an embodiment of the invention which is illustrated in the appended drawings, which are given by way of example and in which:

Fig. 1 is a front view of a counting device of the invention ready for use;

Fig. 2 shows the device, partly in section, after rotation through 90 around its horizontal axis, some parts being broken away;

Fig. 3 is a section along the line IIIIII of Fig. 2;

Fig. 4 is a section along the line IVIV of Fig. 3;

Fig. 5 is a section along the line VV of Fig. 4; and

Fig. 6 is a perspective view of parts of one of the epicyclic trains of the reduction gear.

Broadly, the present invention consists in a counting device comprising a counting mechanism actuatable over a reduction gear having a plurality of epicyclic trains arranged for operating in cascade. The term epicyclic train is used herein in its broadest sense and is intended to embrace what is sometimes called a hypocycloid train.

The invention also consists in a counting device comprising a counting mechanism actuatable over a reduction gear having a plurality of epicyclic trains directly coupled together in cascade, that is to say without any additional coupling mechanism between the epicyclic trains.

In the drawings, a counting device is illustrated for counting the time in hours during which a diesel or other engine has been running. The counting device comprises a casing 1 (see Figs. 1 and 2) having a window 2 through which the number of hours may be read off. Within the casing 1, a frame 3 is provided fixed in the casing 1 in any suitable manner, for example by screws (not shown) and carrying a rotatably mounted driving shaft 4, a counting mechanism generally indicated by reference numeral 5, a reduction gear generally indicated by reference numeral 6, and two additional gears generally indicated by reference numerals 7 and 8, the arrangement being such that the frame 3 and all the parts carried by the said frame may be bodily removed from, and re-inserted into, the casing l, the driving shaft 4- extending out of the easing for connection to a rotating shaft of an engine. In the embodiment shown, the counting mechanism comprises four number wheels 11, each carrying digits 0, l, 9 at its periphery, one digit of each number wheel being visible through the window 2 of the casing 1. Of course, more or less than four number wheels may be provided if desired. The number wheels 11 are mounted on a spindle 12 parallel to the driving shaft 4. The counting mechanism 5 is of any suitable construction and will therefore not be further described in detail.

Over the additional gear 3, which comprises two gear wheels 13 and 14 meshing with each other, the driving shaft 4 is coupled to the reduction gear 6. The reduction gear 6 comprises four epicyclic trains 15 (see also Fig. 4) operable in cascade and arranged on a common spindle 16 parallel to the driving shaft iand to the spindle 12 of the counting mechanism 5. The reduction gear is coupled over the additional gear '7 comprising four gear wheels 17, l8, 15, 2 (see Figs. 2 and 3) to the counting mechanism 5.

Each epicyclic train 15 comprises two members 36' and 31 (see Figs. 4, 5 and 6) mounted on the common spindle 16. The member 30 is provided with a toothed wheel 32 and a fork 33 straddling an element in the shape of a rod 34 fixed to the frame 3. The member 31 is provided with an internally toothed ring 35 integral with a disc 36, to which by means of studs 41 a second disc 33 is keyed which is integral with a hub 37 eccentrical with respect to the discs 33, 36 and the toothed ring 35. The hub 37 has a hole thr ugh which the common spindle 16 extends, the hole re istering with corresponding holes in the discs as and The periphery of the hub 37 slidingly contacts the wall of a hole 43 of the first member 39 of the next following epic clic train (see Fig. 4), the hole 43 being concentric with the toothed wheel 32 of the first member As shown in 5, the internal toothed w eel 32 has 29 teeth while the external toothed ring 3e teeth. Moreover, the toothed Wheel 32 is eccentric with respect to the toothed ring 35, and its teeth, thus, engage only some of the teeth of the toothed ring 35 at any part cular instant.

The wall of the hole 43 of the first member 3% of the first epicyclic train 15 from the left of Fig. 4 slidingly contacts the external circumference of an eccentric hub 371 integral with a disc 331 and the gear wheel 14- of the additional gear The disc 36 of the second mem- 3 her 31 of the last epicyclic train 15 at the right hand side of Fig. 4 is keyed, by means of studs 411, to a cylinder 381 rotatable around the common spindle 16 and carrying, at its circumference, the gear wheel 17 (see also Fig. 2) of the additional gear 7.

The counting device described operates as follows:

Assume that the four epicyclic trains are identical with one another and that the shaft 5 for driving the counting device is connected to the rotating shaft of a diesel 'or other engine so as to rotate therewith. By means of the additional gear 8 the rotation of the driving shaft 4 is transmitted to the eccentric hub 3 71 integral with the gear wheel 14 of the additional gear 8. The eccentric hub 371 is, in its function, analogous to the other eccentric hubs 37. Each of the eccentric hubs when rotated causes the respective toothed wheel 32 bodily to revolve around its centre lying in the axis of the common spindle 16. Rotation of each of the toothed wheels 32 is prevented by the respective fork 33 straddling the rod 34, while the engagement between the fork 33 and the rod 34 allows the toothed wheel to follow the eccentric hub and, thus, to revolve bodily without rotation. When the toothed wheel 32 thus revolves, its teeth come successively into engagement with the teeth of the respective internally toothed ring 35, which is rotatably mounted on the common spindle 16. Now, since the toothed ring 35 has 30 teeth and the toothed wheel 32 has only 29 teeth, there are needed 30 revolutions with out rotations of the toothed wheel 32 to cause the toothed ring 35 to perform one rotation. The rotations of the toothed rings 35 (except that of the last toothed ring at the right-hand side of Fig. 4) cause, over the respective hubs 37, the adjacent respective toothed wheels 32 to revolve without the necessity of providing any additional coupling mechanism between the epicyclic trains. The rotation of the last toothed ring 35 causes the cylinder 381 keyed thereto by the studs 411., and the gear wheel 17 to rotate'with the last toothed ring, the rotation being transmitted by the additional gear 7 to the counting mechanism 5. Since, as just explained, each epicyclic train 15 causes a reduction of the ratio 1/30, the four epicyclic trains 15 operating in cascade cause a reduction of 1/ 810,000, The two additional gears 7 and 8 are so designed that they cause together a further reduction of 1/2, so that a total reduction of the ratio 1/ 1,620,000 is obtained, that is to say 1,620,000 rotations of the driving shaft 4 correspond to one rotation of the spindle 12 of the counting mechanism. Since one such rotation of the counting spindle 12 corresponds to l digits, the counting mechanism moves forward by one unit digit for each 162,000 revolutions of the driving shaft 4. If, instead of four epicyclic trains, five such trains were provided, under otherwise the same conditions, a total reduction of the ratio 1/ 48,600,000 would be obtained, that is to say the counter mechanism would move forward by one unit digit for each 4,860,000 rotations of the driving shaft of the device.

The embodiment described has many advantages. Notwithstanding the high reduction obtainable, the device requires only a reasonably small space and may be given a compact and neat appearance. This is primarily achieved by the use of epicyclic trains for the main reduction gear and by arranging the driving shaft 4 parallel to the spindle 12 of the counting mechanism and the common spindle 16 for the epicyclic trains. As will easily be recognized, there exists a certain freedom of arranging the driving shaft independently of the counting mechanism. In the embodiment shown, the driving shaft 4 is coaxial with the counting device, although the counting mechanism is arranged eccentrieally at one side of the axis of the device.

Of course, it is not necessary that each epicyclic train causes a reduction of the ratio 1/30. By choosing a different ratio that is the same for all the epicyclic trains, or by giving the epicyclic trains reduction ratios that diifer from each other, the device may easily be adapted to different requirements, without changing the general design of the counting device.

Further modifications are possible. For example, the functions of the toothed wheels 32 and the toothed rings 35 may be reversed, that is to say the toothed wheels may be rotatable and provided with eccentric hubs, while the toothed rings are not rotatable but arranged for bodily revolving. Again, the specific kind of epicyclic gears hereinbefore described may be replaced by any other suitable epicyclic gear. The number of teeth of the toothed wheel 32 may differ by more than one from the number of teeth of the toothed ring 35. More, or less, than four epicyclic trains may be provided. The eccentric hubs may be replaced by other suitable devices, for instance by eccentrically arranged studs.

Further modifications, additions and omissions will readily occur to those skilled in the art and, therefore, it is to be clearly understood that the embodiment hereinbefore described with reference to the appended drawings is only given by way of example, and that many modifications, additions and omissions are possible without departing from the spirit of this invention.

We claim:

1. A counting device comprising a counting mechanism including a plurality of number wheels arranged for rotation around a common axis, a driving shaft substantially parallel to said axis, a stationary spindle substantially parallel to said driving shaft, a plurality of epicyclic trains mounted on said spindle and arranged for operating in cascade to constitute a reduction gear, the first of any two successive epicyclic trains operating in cascade having a terminating eccentric member and the second of said two successive epicyclic trains having an initial apertured gear member being substantially equally apertured, the terminating eccentric member of said first of two successive epicyclic trains being in contact with the initial apertured gear member of the second of said two successive epicyclic trains to form a direct coupling between said first and second epicyclic trains, means coupling said driving shaft to one of the plurality of epicyclic trains for driving the reduction gear on rotation of said driving shaft, and means coupling another epicyclic train to said counting mechanism for actuating the same.

2. A counting device comprising a counting mechanism including a plurality of number Wheels arranged for rotation around a common axis, a drixing shaft substantially parallel to said axis, a stationary spindle substantially parallel to said driving shaft, a plurality of epicyclic trains mounted on said spindle and arranged for operating in cascade to constitute a reduction gear, each of said epicyclic trains except the last in the cascade arrangement having a projecting hub portion eccentric with respect to said'spindle which is in contact with an initial apertured gear member of the succeeding epicyclic train in the cascade arrangement to form a direct coupling therewith, the initial apertured gear member of each epicyclic train meshing with a further gear member which rotates therewith the projecting hub portion of the epicyclic train, means for coupling said driving shaft to the initial apertured gear member of the first epicyclic train on said spindle for moving the same on rotation of said driving shaft, and means coupling the last gear member on said spindle to the counting mechanism for actuating the same.

3. A counting device as claimed in claim 2, wherein the initial gear member and the further gear member of each epicyclic train comprise a toothed wheel and an internally toothed ring respectively, the number of teeth of the wheel being different from the number of teeth of the ring, the wheel and the ring being arranged eccentrically relatively to each other, means being provided for locking one of the two gear members against rotation around its centre but allowing the said one member to revolve, without rotation, around the centre of the ther hub being mounted on and rotatable around said other member, the other of the two gear members of spindle, each apertured gear wheel being a sliding fit each pair being mounted rotatably around its centre, on and directly coupled thereby to one of said hubs, whereby when said one member revolves, its teeth suca fork on each gear Wheel in fixed position relative cessively engage the teeth of the said other member 5 thereto and straddling said rod to prevent rotation of causing the same to rotate with a speed different from said gear wheel but allowing the same bodily to revolve, the speed With which the said one member revolves. teeth of. each gear Wheel meshing With teeth of the next 4. A counting device comprising a counting mechanism succeeding gear ring, the number of the teeth of each including a plurality of number wheels arranged for rotagear wheel being different from the number of the teeth tion around a common axis, a driving shaft substantiall 10 or" the next succeeding gear ring, and means coupling the parallel to said axis, a stationary spindle substantially last internally toothed ring to said counting mechanism. parallel to said driving shaft, a stationary rod substantially parallel to said spindle, an eccentric hub mounted PQJEQWHQQS Cited In the 518 of $111.5 Patent on and rotatable around said spindle, means coupling UNiTED STATES {)ATENTS said hub to said driving shaft for rotating said hub on 3.3 rotation of said driving shaft, a plurality of aperturecl 1 g i "jgi g gear Wheels, gearing teeth on each gear Wheel, a plu- 1 f g C r lity of gear rings, gearing teeth internally provided on "i 1924 each gear ring, the said toothed gear wheels and inter- 5 2;, g flstman et 2 nally toothed gear rings being mounted on, and rotatab :0 i 1/34 around, said spindle, and arranged along said spindle in i realyear et a1 P 1935 alternating sequential order, a further eccentric hub on 2334708 Segal 1944 each toothed gear ring except on the last, the said fur- 

